Initial work on meadery app.  Refs #18.

The meadery models are barely started.  More refinements in the fields
need to be done, and methods too.
Changes and additions to models, plus tests.  Refs #18.

Honey changed to kilograms, and methods were added for converting
between mass and volume.  Changed recipe references from "amounts" to
masses and volumes, changed both to use Decimal instead of Integer and
Float.  Added methods to Recipe to predict brew temperature and
specific gravity as well as the beginnings of natural and appellation
checks and added SG correction to samples.

Still haven't added support for sets of ingredients (such as two
different types of honey or flavors) or volume projections for
recipes.
Added support for volume projections.  Refs #18.

Calculates ideal volumes for recipes.
Added preliminary admin and forms support.  Refs #18.

Updated yeast model with tolerance and added tests.  Added admin and
forms support for meadery app.  Added change forms for meadery app and
methods to back them up.
Added support for multiple ingredients.  Refs #18.

It is now possible to have multiple honeys, waters, flavors, or
yeasts.  The admin and forms needs reworking to support this.
Major changes to new meadery app.  Refs #18.

The various menu items are added inline now.

The admin site calculates original and final gravities, both projected and actual.

The admin site now copies both the normal fields and the many-to-many fields.

Categories now work in recipe tests.
Updated admin site and wrapped attributes.  Refs #18.

Also added in some comments to encourage improvements.
Meadery app can now create products.  Finishes #18.

Catalog models needed images disabled for product creation via the
meadery app.
Merge branch 'feature/issue-18' into develop